A new national security agency combining Customs and Immigration officers will oversee Australia's borders, in what the Government is describing as "sweeping new changes" to how Australia's borders are managed.

Australian Border Force (ABF) will begin operating in July next year and will act as the nation's single frontline enforcement agency.

The combined mega-agency follows one of the recommendations in the Commission of Audit.

ABF will be led by a commissioner who will be the nation's "most senior border law enforcement officer" and will focus on border operations.

The commissioner will have the same standing as other security heads including the AFP Commissioner, Chief of the Defence Force and Director General of spy agency ASIO.

The commissioner will report directly to the Immigration Minister and their position will be enshrined in law.

Immigration Minister Scott Morrison says the combined agency will result in "hundreds of millions [of dollars] in savings" but says it is a "reform measure" not a "savings measure" and the money will be reinvested back into the ABF.

Mr Morrison predicts the ABF will be better able to crack down on revenue evasion and deliver more money into Treasury's coffers.

The Minister says ABF will be "intelligence-led, mobile" and "technology enabled", and will operate strategically to ensure officers are deployed "to greatest effect".

"Disciplined, uniformed Border Force officers, some armed, will carry out these tasks and will be supported by mobile and other portable technology which will enhance their ability to clear cargo, remotely access data and information, and wirelessly report back to Strategic Border Command," Mr Morrison told the Lowy Institute in Sydney.

The Federal Government is also planning to buy six new patrol boats so it can patrol inaccessible territories including rivers, estuaries and reefs. Three of them will be deployed in the Torres Strait.

A new intelligence agency and training college will also come under the auspices of the ABF, whose headquarters will be established in Canberra.

ABF will put national security first: Morrison

Mr Morrison has been asked if he will guarantee the ABF will act openly with the Australian media.

Labor has criticised the Government's secrecy surrounding Operation Sovereign Borders and its tactic of refusing to discuss anything relating to an "on-water operation".

The Minister responded saying the force would always put national security first.

"The ABF will put Australia's national security interests first, they'll put the operational integrity issues first, they'll put the safety of their people and those they're coming in contact with first," he said.

"And what other implications that has for how they would engage with the media would be the implications of those priorities being put in place."

Mr Morrison says the reform is only made possible because of the Government's success in stopping the flow of asylum seeker boats.

"We are turning back boats where it is safe to do so," he said.

"This is now the fifth consecutive month during which there has not been a single successful maritime people smuggling venture to Australia.

"A year ago this would have been unthinkable, which was true under the previous government. Their last two immigration ministers, at their best, could not stretch this achievement to a full calendar week.

"By placing safety at the top of our operational requirements, we have established safe and lawful operational procedures, consistent with our international obligations and domestic laws and ensured a safe platform for return on each occasion."

Refugee status determinations given in Manus Island, Nauru

The Immigration Minister says refugee status determinations are being handed down to asylum seekers in detention on Manus Island in Papua New Guinea and Nauru.

"There has been a handful of decisions over the course of the past week splitting about 50-50 positive and negative," he said.

"That will go now through to a resettlement process for those who have had positive decisions."